US Renal Data System 2018 Annual Data Report: Epidemiology of Kidney Disease in the United States

Selective Serotonin Reuptake Inhibitor Use and Hip Fracture Risk Among Patients on Hemodialysis

RATIONALE & OBJECTIVE

Use of selective serotonin reuptake inhibitors (SSRIs) has been associated with hip fracture risk in the general population. This study examined this relationship among patients with kidney failure treated by hemodialysis, a unique high-risk subpopulation, within which the impact of SSRIs on hip fracture risk remains unexplored.

STUDY DESIGN

Case-control study.

SETTINGS & PARTICIPANTS

Eligible cases of hip fracture among maintenance hemodialysis patients between January 1, 2009, and September 30, 2015, were identified using the US Renal Data System. Each case was matched on index date with 10 eligible controls. To be eligible, study participants needed to have more than 1 year of Medicare Parts A and B coverage and more than 3 years of Part D coverage. For a separate examination of new short-term SSRI exposure, we selected cases and controls with more than 18 months of Part D coverage and no prior antidepressant use for 1 year.

EXPOSURE

During the 3-year Part D coverage period, use of SSRIs characterized as any (≥1 prescription filled), low, moderate, and high use (<20%, 20%-<80%, and≥80% of days covered by filled prescriptions, respectively).

OUTCOME

We selected cases using International Classification of Diseases, Ninth Revision codes 820.xx and 821.xx. In addition to 1 of these codes tied to a hospitalization, we required a corresponding surgical procedural code within 7 days of diagnosis.

ANALYTIC APPROACH

Conditional logistic regression to estimate unadjusted and multivariable-adjusted ORs and 95% CIs.

RESULTS

We identified 4,912 cases and 49,120 controls. SSRI use was associated with increased hip fracture risk (adjusted OR, 1.25; 95% CI, 1.17-1.35). Risk for fracture was estimated for any, low, moderate, and high SSRI use: adjusted conditional ORs were 1.25 (95% CI, 1.17-1.35), 1.20 (95% CI, 1.08-1.32), 1.31 (95% CI, 1.18-1.43), and 1.26 (95% CI, 1.12-1.41), respectively. The association between hip fracture events and SSRI use was also seen in the examination of new short-term use (adjusted OR, 1.43; 95% CI, 1.23-1.67).

LIMITATIONS

Biomarkers of mineral bone disorder were not captured and accounted for in this analysis.

CONCLUSIONS

We demonstrated an association between increased hip fracture risk and both long- and new short-term SSRI use. The stronger association with new short-term use may suggest an acute mechanism potentially related to falls.

[Chronic kidney disease-a cardiovascular high-risk constellation]

Chronic kidney disease (CKD) is associated with substantial cardiovascular morbidity and mortality. This is mediated by the high prevalence of traditional cardiovascular risk factors in patients with CKD such as arterial hypertension and diabetes mellitus, but also by the presence of CKD-specific so-called nontraditional cardiovascular risk factors such as vascular calcification, uremic toxins, uremic dyslipidemia as well as inflammation and oxidative stress. Therefore, the primary and secondary prevention of cardiovascular disease represents an integral part of nephrology. This entails optimal control of blood pressure and diabetes, therapy of the uremic dyslipidemia as well as lifestyle-modifying factors such as weight reduction and smoking cessation.

Association of Family Ratings of Quality of End-of-Life Care With Stopping Dialysis Treatment and Receipt of Hospice Services

Importance

Approximately 1 in 4 patients receiving maintenance dialysis for end-stage renal disease eventually stop treatment before death. Little is known about the association of stopping dialysis and quality of end-of-life care.

Objectives

To evaluate the association of stopping dialysis before death with family-rated quality of end-of-life care and whether this association differed according to receipt of hospice services at the time of death.

Design, Setting, and Participants

This survey study included data from 3369 patients who were treated with maintenance dialysis at 111 Department of Veterans Affairs medical centers and died between October 1, 2009, to September 30, 2015. Data set construction and analyses were conducted from September 2017 to July 2019.

Exposure

Cessation of dialysis treatment before death.

Main Outcomes and Measures

Bereaved Family Survey ratings.

Results

Among 3369 patients included, the mean (SD) age at death was 70.6 (10.2) years, and 3320 (98.5%) were male. Overall, 937 patients (27.8%) stopped dialysis before death and 2432 patients (72.2%) continued dialysis treatment until death. Patients who stopped dialysis were more likely to have been receiving hospice services at the time of death than patients who continued dialysis (544 patients [58.1%] vs 430 patients [17.7%]). Overall, 1701 patients (50.5%) had a family member who responded to the Bereaved Family Survey. In adjusted analyses, families were more likely to rate overall quality of end-of-life care as excellent if the patient had stopped dialysis (54.9% vs 45.9%; risk difference, 9.0% [95% CI, 3.3%-14.8%]; P = .002) or continued to receive dialysis but also received hospice services (60.5% vs 40.0%; risk difference, 20.5% [95% CI, 12.2%-28.9%]; P < .001).

Conclusions and Relevance

This survey study found that families rated overall quality of end-of-life care higher for patients who stopped dialysis before death or continued dialysis but received concurrent hospice services. More work to prepare patients for end-of-life decision-making and to expand access to hospice services may help to improve the quality of end-of-life care for patients with end-stage renal disease.

Practical Guide to Vaccination in All Stages of CKD, Including Patients Treated by Dialysis or Kidney Transplantation

Infection is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD), including those receiving maintenance dialysis or with a kidney transplant. Although responses to vaccines are impaired in these populations, immunizations remain an important component of preventative care due to their favorable safety profiles and the high rate of infection in these patients. Most guidelines for patients with CKD focus on the importance of the hepatitis B, influenza, and pneumococcal vaccines in addition to age-appropriate immunizations. More data are needed to determine the clinical efficacy of these immunizations and others in this population and define optimal dosing and timing for administration. Studies have suggested that there may be a benefit to immunization before the onset of dialysis or transplantation because patients with early-stage CKD generally have higher rates of seroconversion. Because nephrologists often serve as primary care physicians for patients with CKD, it is important to understand the role of vaccinations in the preventive care of this patient population.

Surgeon Characteristics and Dialysis Vascular Access Outcomes in the United States: A Retrospective Cohort Study

RATIONALE & OBJECTIVE

An arteriovenous fistula (AVF) is the preferred access for most patients receiving maintenance hemodialysis, but maturation failure remains a challenge. Surgeon characteristics have been proposed as contributors to AVF success. We examined variation in AVF placement and AVF outcomes by surgeon and surgeon characteristics.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

National Medicare claims and web-based data submitted by dialysis facilities on maintenance hemodialysis patients from 2009 through 2015.

EXPOSURES

Patient characteristics, including demographics and comorbid conditions; surgeon characteristics, including specialty, prior volume of AVF placements, and years since medical school graduation.

OUTCOMES

Percent of access placements that were an AVF from 2009 to 2015 (designated AVF placement), and percent of AVFs with successful use within 6 months of placement (maturation) from 2013 to 2014.

ANALYTICAL APPROACH

Multilevel logistic regression models examining the association of surgeon characteristics with the outcomes, adjusted for patient characteristics and dialysis facilities as random effects.

RESULTS

Among 4,959 surgeons placing 467,827 accesses, median AVF placement was 71% (IQR, 59%-84%). More recent year of medical school graduation and general surgery specialty (vs vascular, cardiothoracic, or transplantation surgery) were associated with higher odds of AVF placement. Among 2,770 surgeons placing 49,826 AVFs, the median AVF maturation rate was 59% (IQR, 44%-71%). More recent year of medical school graduation, but not surgical specialty, was associated with higher odds of AVF maturation. Greater prior volume of AVF placement was associated with higher odds of AVF maturation: OR of 1.46 (95% CI, 1.37-1.57) for highest (>84 AVF placements in 2years) versus lowest (<14) volume quintile.

LIMITATIONS

The study relied on administrative data, limiting capture of some factors affecting access outcomes.

CONCLUSIONS

There is substantial surgeon-level variation in AVF placements and AVF maturation. Surgeons' prior volume of AVF placements is strongly associated with AVF maturation.

Mitigating Racial and Sex Disparities in Access to Living Donor Kidney Transplantation: Impact of the Nation's Longest Single-center Kidney Chain

OBJECTIVE

In this study, we sought to assess likelihood of living donor kidney transplantation (LDKT) within a single-center kidney transplant waitlist, by race and sex, after implementation of an incompatible program.

SUMMARY BACKGROUND DATA

Disparities in access to LDKT exist among minority women and may be partially explained by antigen sensitization secondary to prior pregnancies, transplants, or blood transfusions, creating difficulty finding compatible matches. To address these and other obstacles, an incompatible LDKT program, incorporating desensitization and kidney paired donation, was created at our institution.

METHODS

A retrospective cohort study was performed among our kidney transplant waitlist candidates (n = 8895). Multivariable Cox regression was utilized, comparing likelihood of LDKT before (era 1: 01/2007-01/2013) and after (era 2: 01/2013-11/2018) implementation of the incompatible program. Candidates were stratified by race [white vs minority (nonwhite)], sex, and breadth of sensitization.

RESULTS

Program implementation resulted in the nation's longest single-center kidney chain, and likelihood of LDKT increased by 70% for whites [adjusted hazard ratio (aHR) 1.70; 95% confidence interval (CI), 1.46-1.99] and more than 100% for minorities (aHR 2.05; 95% CI, 1.60-2.62). Improvement in access to LDKT was greatest among sensitized minority women [calculated panel reactive antibody (cPRA) 11%-49%: aHR 4.79; 95% CI, 2.27-10.11; cPRA 50%-100%: aHR 4.09; 95% CI, 1.89-8.82].

CONCLUSIONS

Implementation of an incompatible program, and the resulting nation's longest single-center kidney chain, mitigated disparities in access to LDKT among minorities, specifically sensitized women. Extrapolation of this success on a national level may further serve these vulnerable populations.

A Technology Roadmap for Innovative Approaches to Kidney Replacement Therapies: A Catalyst for Change

The number of patients dialyzed for ESKD exceeds 500,000 in the United States and more than 2.6 million people worldwide, with the expectation that the worldwide number will double by 2030. The human cost of health and societal financial cost of ESKD is substantial. Dialytic therapy is associated with an unacceptably high morbidity and mortality rate and poor quality of life. Although innovation in many areas of science has been transformative, there has been little innovation in dialysis or alternatives for kidney replacement therapy (KRT) since its introduction approximately 70 years ago. Advances in kidney biology, stem cells and kidney cell differentiation protocols, biomaterials, sensors, nano/microtechnology, sorbents and engineering, and interdisciplinary approaches and collaborations can lead to disruptive innovation. The Kidney Health Initiative, a public-private partnership between the American Society of Nephrology and the US Food and Drug Administration, has convened a multidisciplinary group to create a technology roadmap for innovative approaches to KRT to address patients' needs. The Roadmap is a living document. It identifies the design criteria that must be considered to replace the myriad functions of the kidney, as well as scientific, technical, regulatory, and payor milestones required to commercialize and provide patient access to KRT alternatives. Various embodiments of potential solutions are discussed, but the Roadmap is agnostic to any particular solution set. System enablers are identified, including vascular access, biomaterial development, biologic and immunologic modulation, function, and safety monitoring. Important Roadmap supporting activities include regulatory alignment and innovative financial incentives and payment pathways. The Roadmap provides estimated timelines for replacement of specific kidney functions so that approaches can be conceptualized in ways that are actionable and attract talented innovators from multiple disciplines. The Roadmap has been used to guide the selection of KidneyX prizes for innovation in KRT.

Patient Navigation: Addressing Social Challenges in Dialysis Patients

Members of racial and ethnic minority groups make up nearly 50% of US patients with end-stage kidney disease and face a disproportionate burden of socioeconomic challenges (ie, low income, job insecurity, low educational attainment, housing instability, and communication challenges) compared with non-Hispanic whites. Patients with end-stage kidney disease who face social challenges often have poor patient-centered and clinical outcomes. These challenges may have a negative impact on quality-of-care performance measures for dialysis facilities caring for primarily minority and low-income patients. One path toward improving outcomes for this group is to develop culturally tailored interventions that provide individualized support, potentially improving patient-centered, clinical, and health system outcomes by addressing social challenges. One such approach is using community-based culturally and linguistically concordant patient navigators, who can serve as a bridge between the patient and the health care system. Evidence points to the effectiveness of patient navigators in the provision of cancer care and, to a lesser extent, caring for people with chronic kidney disease and those who have undergone kidney transplantation. However, little is known about the effectiveness of patient navigators in the care of patients with kidney failure receiving dialysis, who experience a number of remediable social challenges.

Intradialytic Cerebral Hypoperfusion as Mechanism for Cognitive Impairment in Patients on Hemodialysis

The high frequency of cognitive impairment in individuals on hemodialysis is well characterized. In-center hemodialysis patients are disproportionately affected by cognitive impairment compared with other dialysis populations, identifying hemodialysis itself as a possible factor. The pathophysiology of cognitive impairment has multiple components, but vascular-mediated cerebral injury appears to contribute based on studies demonstrating increased cerebral ischemic lesions and atrophy in brain imaging of patients on hemodialysis. Patients on hemodialysis may be at increased risk for cerebral ischemic injury disease due to vasculopathy associated with ESKD and from their comorbid diseases, such as hypertension and diabetes. This review focuses on the intradialytic cerebral hypoperfusion that can occur during routine hemodialysis due to the circulatory stress of hemodialysis. This includes a review of current methods used to monitor intradialytic cerebral perfusion and the structural and functional cognitive outcomes that have been associated with changes in intradialytic cerebral perfusion. Monitoring of intradialytic cerebral perfusion may become clinically relevant as nephrologists try to avoid the cognitive complications seen with hemodialysis. Identifying the appropriate methods to assess risk for cerebral ischemic injury and the relationship of intradialytic cerebral hypoperfusion to cognitive outcomes will help inform the decision to use intradialytic cerebral perfusion monitoring in the clinical setting as part of a strategy to prevent cognitive decline.

Ratio of Early Mitral Inflow Velocity to the Global Diastolic Strain Rate and Global Left Ventricular Longitudinal Systolic Strain Predict Overall Mortality and Major Adverse Cardiovascular Events in Hemodialysis Patients

Background

The ratio of early mitral inflow velocity to the global diastolic strain rate (E/E'sr) and global longitudinal systolic strain (GLS) of the left ventricle (LV) are emerging indices of diastolic and systolic functions, respectively, for the LV. Their prognostic significance in the prediction of mortality and cardiovascular (CV) outcomes remains underexplored in hemodialysis (HD) patients.

Methods

This prospective study included 190 maintenance HD patients. The E/E'sr ratio and GLS were assessed using two-dimensional speckle tracking echocardiography. The clinical outcomes included overall mortality, CV mortality, and major adverse cardiovascular events (MACE). The associations between the E/E'sr ratio, GLS, and clinical outcomes were evaluated using multivariate Cox regression analysis. The incremental values of the E/E'sr ratio and GLS in outcome prediction were assessed by χ ² changes in Cox models.

Results

Over a median follow-up period of 3.7 years, there were 35 overall deaths, 16 CV deaths, and 45 MACE. Impaired diastolic function with a higher E/E'sr ratio was associated with overall mortality (HR, 1.484; 95% CI, 1.201-1.834; p < 0.001), CV mortality (HR, 1.584; 95% CI, 1.058-2.371; p = 0.025), and MACE (HR, 1.205; 95% CI, 1.040-1.397; p = 0.013) in multivariate adjusted Cox analysis. Worsening GLS was associated with overall mortality (HR, 1.276; 95% CI, 1.101-1.480; p = 0.001), CV mortality (HR, 1.513; 95% CI, 1.088-2.104; p = 0.014), and MACE (HR, 1.214; 95% CI, 1.103-1.337; p < 0.001). The E/E'sr ratio and GLS had better outcome prediction than the E to early diastolic mitral annular velocity (E/E') ratio and left ventricular ejection fraction (LVEF). Moreover, adding the E/E'sr ratio and GLS to Cox models containing relevant clinical and conventional echocardiographic parameters improved the prediction of overall mortality (p < 0.001), CV mortality (p < 0.001), and MACE (p < 0.001).

Conclusion

The E/E'sr ratio and GLS, as emerging indices of LV diastolic and systolic functions, significantly predict mortality and CV outcomes and outperform conventional echocardiographic parameters in outcome prediction in HD patients.

Revascularization Strategies in Patients with Chronic Kidney Disease and Acute Coronary Syndromes

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is a highly prevalent condition that increases the incidence and complexity of acute coronary syndrome (ACS). The purpose of this review is to summarize current evidence, uncertainties, and opportunities in the management of patients with CKD and ACS, with a focus on revascularization.

RECENT FINDINGS

Patients with CKD have been systematically under-represented or excluded from clinical trials in ACS. Available data, however, demonstrates that although patients with CKD and ACS benefit from revascularization, they are also less likely to receive recommended medical and revascularization therapies when compared to patients with normal kidney function. Despite the increased short-term risk of major morbidity and mortality, patients with CKD and ACS should be considered for an early invasive strategy while also trying to mitigate the risks of procedural related complications. Until evidence emerges from randomized clinical trials, the decision about revascularization strategy should involve multi-disciplinary collaboration, heart team consensus, and patient shared decision-making.

Optimized nonviral gene delivery for primary urinary renal progenitor cells to enhance cell migration

Progressive loss of glomerular podocytes during kidney disease leads to irreversible kidney failure, and is exacerbated by the fact that podocytes are terminally differentiated epithelial cells and unable to proliferate. Regeneration of lost podocytes must therefore derive from nonpodocyte sources. Human urine-derived renal progenitor cells (uRPCs) are attractive podocyte progenitors for cell therapy applications due to their availability from patient urine and ability to migrate to injured glomeruli and differentiate into de novo podocytes after intravenous administration. Because gene delivery has emerged as an important strategy to augment the functionality and survival of cell therapies prior to injection, in this work we optimized nonviral gene delivery conditions (cell density, DNA dose, % FBS, and transfection material composition) to primary uRPCs. Using the cationic polymer-peptide conjugate VIPER for gene delivery and the Sleeping Beauty transposon/transposase constructs for gene integration, we optimized transfection parameters to achieve efficient transgene expression (up to 55% transfected cells) and stable transgene expression (>65% integration efficiency) lasting up to 10 days. With these methods, we transfected uRPCs to overexpress CXCR4, an important chemokine receptor that mediates uRPC migration to the kidneys after intravenous injection, and demonstrate that CXCR4-uRPCs exhibit enhanced migration compared to mock-transfected cells.

Use of Percutaneous Coronary Intervention Among Black and White Patients With End-Stage Renal Disease in the United States

Background Racial disparities in invasive cardiac procedures such as percutaneous coronary intervention (PCI) in the general population are well documented; however, national-level data on such disparities in the end-stage renal disease (ESRD) population are lacking. We assessed racial differences in PCI between black and white patients with ESRD on maintenance dialysis. Methods and Results Using the US Renal Data System database, we abstracted Medicare inpatient procedure claims for PCI in a cohort of 268 575 Medicare-primary patients who initiated treatment on maintenance dialysis from January 1, 2009, through June 1, 2013. We conducted Cox regression analyses with PCI being the event, adjusted for demographic characteristics, Hispanic ethnicity, cause of ESRD, comorbidities, and socioeconomic factors. We also assessed the probability of PCI, accounting for death or transplant in competing risk regression models. The crude incidence rate of PCI among white patients was 25.8 per 1000 patient-years versus 15.5 per 1000 patient-years among black patients. Cox regression analyses demonstrated that black patients were significantly less likely to undergo PCI compared with white patients (adjusted hazard ratio: 0.64; 95% CI, 0.62-0.67; P<0.001). In the competing risk models, the racial gap for PCI among black and white patients remained significant with death (subdistribution hazard ratio: 0.81; 95% CI, 0.76-0.85; P<0.001) or transplant as a competing event (subdistribution hazard ratio: 0.67; 95% CI, 0.64-0.70; P<0.001). Conclusions A racial gap exists in PCI use among dialysis patients despite having comprehensive coverage with Medicare. These findings persisted despite accounting for demographic, clinical, socioeconomic factors, and death or transplant as competing events.

Paying for Frequent Dialysis

In late 2017, the 7 regional contractors responsible for paying dialysis claims in Medicare proposed new payment rules that would restrict payment for hemodialysis treatments in excess of 3 weekly to exceptional acute-care circumstances. Frequent hemodialysis is performed more frequently than the traditional thrice-weekly pattern, and many stakeholders-patients, providers, dialysis machine manufacturers, and others-have expressed concern that these payment rules will inhibit the growth of this treatment modality's use among US dialysis patients. In this Perspective, we explain the role of these contractors in the context of Medicare's in-center hemodialysis-centric dialysis payment system and assess how well this system accommodates the higher treatment frequencies of both peritoneal dialysis and frequent hemodialysis. Then, given the available evidence concerning the relative effectiveness of these modalities versus thrice-weekly in-center hemodialysis and trends in their use, we discuss options for modifying Medicare's payment system to support frequent dialysis.

Ultrafiltration-profiled hemodialysis to reduce dialysis-related cardiovascular stress: Study protocol for a randomized controlled trial

Rapid fluid removal (ultrafiltration, UF) is associated with higher cardiovascular morbidity and mortality among individuals receiving maintenance hemodialysis (HD). Fluid removal rates that exceed vascular refill rates can result in hemodynamic instability, end-organ damage to the heart, kidneys, gut and brain, among other organs, and patient symptoms. There are no known evidence-based HD treatment strategies to reduce harm from higher UF rates. Ultrafiltration profiling, the practice of varying UF rates to maximize fluid removal during periods of greatest hydration and plasma oncotic pressure, has been proposed as an HD treatment intervention that may reduce UF rate-related complications. This study is a randomized 4-phase cross-over trial in which participants are successively alternated between study arms with intervening washout periods, and treatment order is randomized. After 4-week screening and 6-week baseline periods, participants are randomized to HD with conventional UF or HD with UF profiling for a period of 3 weeks followed by a 1-week washout period before crossing over. Participants cross into conventional UF and UF profiling phases twice (2 phases per arm). The primary outcomes of interest are intradialytic hypotension (nadir intradialytic systolic blood pressure <90 mmHg), pre-to post-HD change in troponin T (expressed as a percentage), change in left ventricular global longitudinal strain (an echocardiographic measure of left ventricular systolic function), and development of intradialytic left ventricular stunning (worsening of contractile function in ≥2 segments). This study will determine the impact of UF profiling on UF rate-related cardiovascular complications in prevalent, maintenance HD patients.

Frequency and Consequences of Acute Kidney Injury in Patients With CKD: A Registry Study in Queensland Australia

Background

Acute kidney injury (AKI) contributes to and complicates chronic kidney disease (CKD). We describe AKI documented in hospital encounters in patients with CKD from the CKD Queensland registry.

Study Design

A retrospective cohort study during 2011 to 2016.

Setting & Participants

Participants had been admitted to a hospital in Queensland.

Predictors

AKI was identified from International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification codes.

Outcomes

All-cause mortality with or without kidney replacement therapy (KRT), start-up KRT and maintenance KRT, costs of care.

Analytical Approach

Time to outcomes for those with versus without AKI was evaluated using Cox regression models. Mann-Whitney test was used to compare number of admissions, hospitalized days and costs by AKI status.

Results

Among 6,365 patients followed up for up to 5.4 years, 2,199 (35%) had 4,711 hospital encounters with an AKI diagnosis. Those with AKI were older (68 vs 64 years old), were more often men (36.7% vs 32.2%; P < 0.001), had more advanced CKD stages (stage 3b, 34%; stage 4, 35%; and stage 5, 10%), had more admissions (12 vs 5; P < 0.001), and stayed in the hospital longer (56 vs 14 days; P < 0.001) than those without AKI. Almost 90% of AKI admissions were through the emergency department. Of those with AKI, 554 (25%) subsequently died without any form of KRT and 285 (13%) started KRT, compared with 282 (6.8%) who died and 315 (7.6%) who started KRT among those without AKI; P < 0.001 for each. Adjusted for other significant factors, hazard ratios for all deaths or death without KRT were 2.95 (95% CI, 2.56-3.39; P < 0.001) and 3.02 (95% CI, 2.60-3.51; P < 0.001), respectively, in patients with AKI relative to those without AKI. The hazard ratio for all KRT was 1.40 (95% CI, 1.18-1.66; P < 0.001), and for maintenance KRT was 1.21 (95% CI, 0.98-1.48; P = 0.07). Mean total hospital cost in patients with AKI was more than triple that of patients with no AKI (A $93,042 vs A $30,778; P < 0.001).

Limitations

These findings may not be generalizable to CKD populations from the general community or in other health care environments.

Conclusions

AKI is associated with strikingly increased deaths, increased rates of KRT, and higher hospital costs.

Toxicological Risk Assessments of Iron Oxide Nanocluster- and Gadolinium-Based T1MRI Contrast Agents in Renal Failure Rats

Gadolinium-based contrast agents (GBCAs) are widely used for T1-weighted magnetic resonance imaging (MRI) in clinic diagnosis. However, a major drawback of GBCAs is that they can increase the toxicological risk of nephrogenic systemic fibrosis (NSF) in patients with advanced renal dysfunction. Hence, safer alternatives to GBCAs are currently in demand, especially for patients with renal diseases. Here we investigated the potential of polyethylene glycol (PEG)-stabilized iron oxide nanoclusters (IONCs) as biocompatible T1MRI contrast agents and systematically evaluated their NSF-related risk in rats with renal failure. We profiled the distribution, excretion, histopathological alterations, and fibrotic gene expressions after administration of IONCs and GBCAs. Our results showed that, compared with GBCAs, IONCs exhibited dramatically improved biosafety and a much lower risk of causing NSF, suggesting the feasibility of substituting GBCAs with IONCs in clinical MRI diagnosis of patients with renal diseases.

Microfluidic DNA-based potassium nanosensors for improved dialysis treatment

BACKGROUND

Patients with end-stage renal disease (ESRD) have failed kidney function, and often must be treated with hemodialysis to extend the patient's life by artificially removing excess fluid and toxins from the blood. However, life-threatening treatment complications can occur because hemodialysis protocols are adjusted infrequently, as opposed to the kidneys which filter blood continuously. Infrequent blood tests, about once per month on average, are used to adjust hemodialysis protocols and as a result, patients can experience electrolyte imbalances, which can contribute to premature patient deaths from treatment complications, such as sudden cardiac death. Since hemodialysis can lead to blood loss, drawing additional blood for tests to assess the patient's kidney function and blood markers is limited. However, sampling multiple drops of blood per session using a microfluidic device has the potential to reduce not only the amount of blood drawn and avoid unnecessary venipuncture, but also reduce costs by limiting medical complications of hemodialysis and provide a more comprehensive assessment of the patient's health status in real time.

RESULT

We present preliminary proof-of-concept results of a microfluidic device which uses DNA-based fluorescence nanosensors to measure potassium concentration in a flowing solution. In a matter of minutes, the flowing potassium solution reduced the fluorescence intensity of the nanosensors to a steady-state value.

CONCLUSIONS

These proof-of-concept results demonstrate the ability of our DNA-based nanosensors to measure potassium concentration in a microfluidic device. The long-term goal is to integrate this technology with a device to measure potassium and eventually other blood contents multiple times throughout a hemodialysis session, enabling protocol adjustment similar to a healthy kidney.

Blood Pressure and Incident Atrial Fibrillation in Older Patients Initiating Hemodialysis

BACKGROUND AND OBJECTIVES

We examined the association of predialysis systolic and diastolic BP and intradialytic hypotension with incident atrial fibrillation in older patients initiating hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used the US Renal Data System linked to the records of a large dialysis provider to identify patients aged ≥67 years initiating hemodialysis between January 2006 and October 2011. We examined quarterly average predialysis systolic BP, diastolic BP, and proportion of sessions with intradialytic hypotension (i.e., nadir systolic BP <90 mm Hg). We applied an extended Cox model to compute adjusted hazard ratios (HRs) of each exposure with incident atrial fibrillation.

RESULTS

Among 17,003 patients, 3785 developed atrial fibrillation. When comparing predialysis systolic BP to a fixed reference of 140 mm Hg, lower predialysis systolic BP was associated with a higher hazard of atrial fibrillation, whereas higher systolic BP was associated with a lower hazard of atrial fibrillation. When comparing across a range of systolic BP for two hypothetical patients with similar measured covariates, the association varied by mean systolic BP: at systolic BP 190 mm Hg, each 10 mm Hg lower systolic BP was associated with lower atrial fibrillation hazard (HR, 0.94; 95% confidence interval, 0.90 to 1.00), whereas at systolic BP 140 mm Hg, a 10 mm Hg lower systolic BP was associated with a higher atrial fibrillation hazard (HR, 1.12; 95% confidence interval, 1.10 to 1.14). Lower diastolic BP was associated with higher atrial fibrillation hazards. Intradialytic hypotension was weakly associated with atrial fibrillation.

CONCLUSIONS

In this observational study of older patients initiating hemodialysis, lower predialysis systolic BP and diastolic BP were associated with higher incidence of atrial fibrillation.

Renal function and oral anticoagulant treatment of incident non-valvular atrial fibrillation: a retrospective study

Aim: To describe the renal function of individuals newly diagnosed with non-valvular atrial fibrillation in England, and describe how oral anticoagulant (OAC) treatment varies according to renal function. Patients & methods: We identified a cohort of individuals with non-valvular atrial fibrillation (n = 18,419) and described their renal function at diagnosis and the prevalence of OAC treatment initiation by renal function. Results: 79% of individuals had some evidence of renal dysfunction with 12% having a glomerular filtration rate <30 ml/min/1.73 m². OAC treatment initiation in the 6 months following diagnosis was lower in individuals with severe renal dysfunction than in those with normal renal function. Conclusion: The high prevalence of renal dysfunction and low OAC treatment prevalence highlights the need for additional evidence regarding OACs in individuals with severe renal dysfunction.

Effectiveness of Dose Adjustment of Insulin in Type 2 Diabetes among Hemodialysis Patients with End-Stage Renal Disease: A Randomized Crossover Study

Determining insulin requirements for hemodialysis patients with end-stage renal disease (ESRD) is difficult. We performed a randomized crossover study among type 2 diabetes (T2DM) patients with ESRD on continuous hemodialysis and receiving standard insulin for glycemic control. The patients were randomized in 2 groups: daily insulin needed on the day after hemodialysis and a 25% decrease in daily insulin needed on the day after hemodialysis. A total of 51 T2DM patients with ESRD were enrolled. The adjusted-insulin group had higher plasma glucose levels at the 2nd hour of dialysis than those of the nonadjusted-insulin group. Incidence of hypoglycemia per dialysis session (3.3% vs. 0.7%, P = 0.02) and symptoms related to hypoglycemia (6.9% vs. 0.7%, P = 0.001) were more frequent in the nonadjusted-insulin group. A reduced insulin administration of 25% among T2DM patients undergoing hemodialysis on the day of dialysis was associated with sustained glycemic efficacy and the production of fewer hypoglycemic symptoms. This trial is registered with TCTR20180724002.

Chinese Herbal Medicine in Ameliorating Diabetic Kidney Disease via Activating Autophagy

Diabetic kidney disease (DKD), a leading cause of end-stage renal disease (ESRD), has become a serious public health problem worldwide and lacks effective therapies due to its complex pathogenesis. Recent studies suggested defective autophagy involved in the pathogenesis and progression of DKD. Chinese herbal medicine, as an emerging option for the treatment of DKD, could improve diabetic kidney injury by activating autophagy. In this review, we briefly summarize underlying mechanisms of autophagy dysregulation in DKD, including AMP-activated protein kinase (AMPK), the mechanistic target of rapamycin (mTOR), and the sirtuin (Sirt) pathways, and we particularly concentrate on the current status of Chinese herbal medicine treating DKD by regulating autophagy. The advances in our understanding regarding the treatment of DKD via regulating autophagy with Chinese herbal medicine will enhance the clinical application of Chinese medicine as well as discovery of novel therapeutic agents for diabetic patients.